Playing court



June 7, 1932. K. .w. OTTO PLAYING COURT Filed Sept. 17, 1928 PatentedJune 7, 1932 UNITED STATES KURT-WILLY OT TO, OF BAD PYRMONT, GERMANYPLAYING COURT Application filed September 17, 1928, Serial No. 306,416,and in Germany September 20, 1927.

providing a layer of brick or ashes and then applying horizontallythereto one or more finer layers of a suitable covering material. Tomake the court perfectly faultless this covering material requires onthe one hand to create a sufficient binding force that, by

means of rolling, a flat, elastic and composite surface may be producedfrom the same, while on the other hand this material neverthelessrequires to be so pervious to moisture,

' or capable of absorbing moisture, that after a shower of rain thecourt may again be used within a very short time.

Sand, brick dust and mire courts are certainly extremely pervious tomoisture, but bind to so little extent that the same become very dustyin warm weather and also greatly cut up in use, so that they lose inelasticity.

Clay, marl and gravel courts are certainly always elastic and free fromdust; the same,

I however, remain too moist after a shower of rain, and in order toprevent their absorbing too much water they require to be furnished withdrops towards one or more sides. The irregularity of the surface thusoccasioned on both sides is extremely undesirable.

Now it is the object of the present invention to overcome thedisadvantages referred to.

According to the invention the arrangement is such that layers ofmaterial pervious to moisture penetrate more or less in scollop formlayers of material less pervious to moisture. The penetration may besuch that the surface of the pervious layer may be varied in proportionto the surface of the less pervious layer where the two meet, viz., inaccordance with climate and the fall of rain.

The invention will now be described more fully with reference to theaccompanying drawing, in which Figs. 1a, 1b, 10, and 10? are sectionsshowing diflerent constructions of tennis courts,

Fig. 2 being a detail.

Referring now to the drawing, the pervious layer is designated by 1, andthe less pervious layer by 2. These layers are not only disposedhorizontally one above the other but, as shown in Figs. 1a and lb,vertically one through the other, i. e., the layer 1 pervious tomoisture penetrates with scollops, teeth or other elevations orprojections through the layer 2 less pervious to moisture.

Both layers serve different purposes in accordance with theirpeculiarity; the layer or top (sections 1a and 1b), whilein the case ofa dry climate the projections will be arranged in the reverse order, i.e., with the apex towards the top, so that the surface of the court willcertainly be drained but nevertheless not entirely parched (sections 10and 1d).

The court according to the invention is produced with the assistance ofa tapered iron rod, the dimensions and shape of which are selected inaccordance with the normal fall of rain in the particular locality thisrod being employed to make holes in the rolled, less pervious layerextending as far as the layer of ashes situated thereunder, whereuponthe holes are filled with sand, fine gravel or thelike.

The iron rod may also be hollow and arranged to receive a filling ofsand. By depressing a lever a valve is opened allowing the sand to passinto the holes. It is of course als: possible to employ a plurality ofthese ro s.

A court in which the conical projections are situated with their basestowards the bottom is produced. with the assistance of the device shownin Fig. 2. This latter consists of fired clay, plaster, sheet metal orthe like. The rings in which the drainage openings are situated arecovered with moist sand, so that the openings will not be choked orclogged by the material less pervious to moisture. The members thusprepared are placed upon the rolled layer of ashes or the like,whereupon the layer of less pervious material is applied in suchthickness that the tips of the hollow members will not be damaged whenthe upper layer is being rolled. If the openings are insufficient in thecase of a heavy fall of rain,

or if the layer of less pervious material is.

relatively thin, consideration to these conditions may be paid by makingthe members frusto-conical in form. The upper surface of such a memberwill be in the form of a crater, i. e., depressed, and furnished with adrainage hole. The craters formed may be filled out with small stones.

It will be understood that no restriction is made to the exactembodiments shown, and that various other forms may be devised withoutdeparting from the spirit of the invention.

One embodiment of my invention is constructed as follows On a firmlyrolled layer of slag, which is furnished with a drainage, there isapplied a layer of water storing gravel or marl of a few centimetres inthickness, the single particles of which are surrounded by particles ofclay or intimately mixed therewith. This layer, due to its waterabsorbing properties, maintains the court for a long time in a moist andelastic condition. To prevent the same, however, from storing too muchwater and thus becoming too soft, there are provided therein by means ofa suitably constructed spike, a number of conical holes having adiameter of between 6 7 cm. at the top and a diameter of between 2-3 cm.at the bottom, where they open out into the layer of slag. These holeswhich cover the whole court at distances apart amounting toapproximately 15 cm. are filled out with line gravel etc. and reach fromthe surface of the marl into the layer of slag. The holes are filled outwith gravel to approximately three-quarters of their depth, theremainder being filled with the same material forming the upper layer ofthe court, so that the latter does not roll on to the gravel or becomedetached therefrom. In place of gravel it is also possible to employground stone or artificial stone having a size of grain amounting to 48mm.

The upper playing surface consists of finely ground artificial ornatural stone or sand, having admixed therewith approximately 1020% offinely ground marl as employed in the water absorbing layer, so that thebinding and the capillary action of this layer is increased The layer inquestion sucks up the rain and passes the same to the water absorbinglayer and via the projectory portions to the layer of slag. Theseprojectory portions accordingly act in the manner of drains. When rainceases to fall the playing surface dries very rapidly, the same being atonce freed from the main amount of water falling on to the same. If, onthe other hand, the playing surface should dry to a too great extent,the same, by reason of the capillary action, obtains fresh moisture fromthe storage layer situated thereunder. The court therefore iscontinuously in a slightly moist and bound condition, i. e. in an idealcondition for playing purposes.

l/Vhat I claim as new and desire to secure by Letters Patent is:

1. In a playing court, a layer of covering material pervious tomoisture, and a second layer less previous to moisture, the saidpervious layer penetrating the less pervious layer in its entirethickness and having the effect of conducting away the water.

2. In a playing court, a layer of covering material pervious tomoisture, and a second layer less pervious to moisture, the saidpervious layer penetrating with conical projections the said layer lesspervious to moisture, said projections extending entirely through theless pervious layer and having the effect of conducting away the water.

3. In a playing court, a layer of covering material pervious tomoisture, and a second layer less pervious to moisture and penetrated byprojections of the said pervious layer, whereby the surface of the saidpervious layer in proportion to the said less pervious layer may bevaried where the two meet in accordance with climatical conditions andthe normal fall of rain in the particular locality, said projectionsextending entirely through the less pervious layer and having the effectof conducting away the water.

4. In a playing court, a layer of cover ing material pervious tomoisture, and a second layer less pervious to moisture and penetrated byprojections proceeding from the said pervious layer, the saidprojections be ing of a different material to the said layers andserving to conduct away the water and extending entirely through theless pervious layer.

In testimony whereof I have affixed my signature.

KURT-VVILLY OTTO.

